1. Field of the Invention
The invention relates to an evaporative fuel treatment apparatus.
2. Description of Related Art
Japanese Patent Application Publication No. 04-287860 (JP 04-287860 A) discloses a evaporative fuel treatment apparatus that includes a compressor of a supercharger, a canister, a purge open/close valve and a fail-safe open/close valve. The compressor of the supercharger is provided upstream of a throttle valve in an intake passage of an engine. The canister adsorbs evaporative fuel that is developed in a fuel tank, and is used to guide evaporative fuel via a purge passage to a downstream side of the throttle valve in the intake passage. The purge open/close valve is provided in the purge passage, and controls a purge amount of evaporative fuel. The fail-safe open/close valve is provided in the purge passage. One of chambers is comparted in the fail-safe open/close valve by a diaphragm such that the purge passage is closed at the time when the throttle valve is fully closed communicates with the intake passage at a portion downstream of the throttle valve. The other one of the chambers comparted by the diaphragm in the fail-safe open/close valve communicates with the intake passage at a portion near a downstream side of the compressor of the supercharger.